Hot air blower-type track switch snow melters have become standard equipment for railroads operating in cold climates. For those railroads, snow and ice buildup at track switches is a problem and track switch snow melters have become the solution of choice. With track switch snow melters, rather than laboriously clearing switches of snow by hand, this task can be done automatically.
Track switch snow melters generally have a plurality of snow sensors that detect the presence of snow in switching areas. These sensors relay a signal to a control panel on a heat source or blower unit. When snow is detected, hot air is blown through a system of ducts which direct a stream of hot air through various nozzles and outlets to critical areas of the switch which must be kept free of snow and ice.
The placement of the duct work is a difficult and critical aspect of the installation of hot air blowers. The ducts must be both proximate the rails so that the hot air can melt the snow and ice around them and at the same time not obstruct passing trains. One arrangement that has been used to accomplish these dual objectives is to place a first duct running from the heat source parallel and between two ties and beneath the rails of the track. From this first duct, low profile nozzles have been extended to direct hot air at critical parts of the switching mechanism. In addition to nozzles, additional ducts have been extended from the first duct perpendicular to the ties and parallel to the rails. These ducts are placed above the ties. Straps have been used to bolt these ducts to the ties. Ports or openings along the sides of the ducts directed air to areas to be kept clear of snow and ice.
Although the track switch snow melters have been important labor savers for keeping track switches clear of snow and ice, the duct work must be removed whenever the track is routinely maintained. With prior configurations of the duct work, this was a time-consuming process. In particular, the first duct had to be pulled out from between the ties in one segment. This segment was approximately as long as one of the ties. Considerable effort was required to slide the segment out because of friction created between the sides of the segment and the ballast. Flanges protruding from the segment also engaged the ballast making it difficult to slide out the segment.